Trace gas in electrical equipment is commonly found in electrical insulating oil used in electrical equipment, which may perform any number of functions in generation, transmission and distribution of electrical power. Some examples of electrical equipment include transformers, tap-changers and circuit breakers. When a fault occurs within the electrical equipment, a trace gas (i.e., a fault gas) may be generated and becomes dissolved in the electrical insulating oil.
The trace gases are extracted from an oil sample obtained from the electrical equipment and measured by a measurement device. The trace gas measurements are used to provide an operational and health status of the electrical equipment. For example, in a transformer, when faults, e.g., arcing and overheating occur, gases such as methane and carbon dioxide or carbon monoxide are present in the insulating oil of the transformer. Measurements of these trace gases can be used to determine the type and the severity of the faults which occur in the electrical equipment.
A measurement device such as a photoacoustic spectroscope are typically used to obtain trace gas measurements such as methane, ethane, ethylene and other trace gases with the exception of hydrogen, where small vibrations of the molecules in the trace gases are generated when subjected to a particular infrared (IR) frequencies of light. Hydrogen is generated as a result of several fault conditions, e.g., oil or other insulation overheating, oxidation issues and arcing. In addition, the presence of hydrogen in trace gases is indicative of a low energy potential difference.